John Sankey wrote:
K is potassium, an alkali. Yes, it will raise pH.
I use a water-softening resin (after chloramine removal)
then find that sulphuric acid (pH lower) added slowly over a
week bring pH to 6.5, which is where I want it for
trichogaster breeding. No bounce if you add it slowly, allowing
everything to settle between additions.


No, K+ will not raise pH, just like adding table salt, NaCl will not
raise pH either.
To raise pH, you need a buffer, K+, is not a buffer nor is NO3.
KNO3 is a salt.
Common name: saltpeter........

Better to use RO water to lower KH, than H2SO4, a rather nasty strong
acid, HCL, HNO3, may also be used, or peat.

RO water is the best solution and one used in most hobby tanks.

Regards,
Tom Barr

www.BarrReport.com
The aquatic horticulture on line magazine for aquatic plants